Tremolo or vibrato devices for special effects are well known to those skilled in the guitar art. In fact, various devices of this kind, having different structural configurations, are presently available in the market place. The devices allow the guitarist to provide a vibrato effect to alter the tone of the instrument by rapidly increasing or decreasing the string tension during play. This alteration in tension is brought about by back and forth movement of the tremolo device by a hand lever that is capable of transmitting a substantial stretching force to the strings. This force, particularly under the most demanding playing conditions, leads to slight slippage of the strings over the baseplate of the assembly, and the subsequent failure of the guitar to return to the original tune. Also, the detuning may result from simply a slight stretching of the strings beyond the elastic limit.
In the past, little attention has been paid to improving the nut assembly, either in terms of improving the holding ability or providing for quick release and readjustment. U.S. Pat. No. 4,171,661 to Rose discloses blocks held by single bolts or screws for clamping the strings of the guitar at the nut assembly. Specifically, the nut assembly includes a series of rigid blocks each clamping a pair of strings on a baseplate by means of a single screw. The blocks overlie the strings and hold them in proper position within the slots when the screws are tightened, the strings being released for returning of the instrument when the screws are all loosened.
The Rose nut assembly suffers from a serious drawback. In order to retune a guitar fitted with the Rose tremolo apparatus, it is necessary to use a separate wrench or screwdriver to loosen the blocks and allow adjustment of the string tension. This time consuming and tedious operation is particularly inconvenient during a live performance. Additionally, the needed tools may not be available on stage or during a recording session when an audience and/or a highly paid sound technician is left sitting and waiting. Indeed, some guitar manufacturers have recognized the problem but have attempted to solve it in a patchwork manner by attaching a tool holder to the backside of the pegboard of the guitar. While the tool is then usually more convenient, it is subject to be lost, or even fall out at the most inopportune times, and requires an inordinate amount of time to remove the tool, make the adjustment and return the tool to the holder.
Thus, a need is identified for a locking nut assembly that maintains the original tune of the guitar after tremolo play while also allowing simple and efficient returning without the need of additional tools. As yet, this need is unaddressed in the art.